Liquid panel assembly

ABSTRACT

A liquid panel assembly configured to be used with an energy exchanger may include a support frame having one or more fluid circuits and at least one membrane secured to the support frame. Each of the fluid circuits may include an inlet channel connected to an outlet channel through one or more flow passages. A liquid is configured to flow through the fluid circuits and contact interior surfaces of the membrane(s). The fluid circuits are configured to at least partially offset liquid hydrostatic pressure with friction loss of the liquid flowing within the fluid circuits to minimize, eliminate, or otherwise reduce pressure within the liquid panel assembly.

CROSS REFERENCE TO RELATED APPLICATION

The present application is a continuation of U.S. application Ser. No.17/231,634, filed Apr. 15, 2021, entitled “Liquid Panel Assembly,” whichis a continuation of U.S. application Ser. No. 15/590,685, filed May 9,2017, entitled “Liquid Panel Assembly,” which is a continuation of U.S.application Ser. No. 13/797,152, filed Mar. 12, 2013, entitled “LiquidPanel Assembly,” which is a Non-Provisional and claims priority fromU.S. Provisional Application Ser. No. 61/774,192 filed Mar. 7, 2013,entitled “Liquid Panel Assembly”, which related and claims priority fromU.S. Provisional Application Ser. No. 61/692,798 filed Aug. 24, 2012,entitled “Liquid Panel Assembly,” which are hereby expresslyincorporated by reference in their entirety.

BACKGROUND OF THE DISCLOSURE

Embodiments of the present disclosure generally relate to a liquid panelassembly, and more particularly, to a liquid panel assembly configuredfor use with an energy exchanger.

Enclosed structures, such as occupied buildings, factories and the like,generally include a heating/ventilation/air conditioning (HVAC) systemfor conditioning outdoor ventilated and/or recirculated air. The HVACsystem includes a supply air flow path and an exhaust air flow path. Thesupply air flow path receives pre-conditioned air, for example outsideair or outside air mixed with re-circulated air, and channels anddistributes the pre-conditioned air into the enclosed structure. Thepre-conditioned air is conditioned by the HVAC system to provide adesired temperature and humidity of supply air discharged into theenclosed structure. The exhaust air flow path discharges air back to theenvironment outside the structure. Without energy recovery, conditioningthe supply air typically requires a significant amount of auxiliaryenergy, particularly in environments having extreme outside airconditions that are much different than the required supply airtemperature and humidity. Accordingly, energy exchange or recoverysystems are used to recover energy from the exhaust air flow path.Energy recovered from air in the exhaust flow path is utilized to reducethe energy required to condition the supply air.

Conventional energy exchange systems may utilize energy recovery devices(for example, energy wheels and permeable plate exchangers) or heatexchange devices (for example, heat wheels, plate exchangers, heat-pipeexchangers and run-around heat exchangers) positioned in both the supplyair flow path and the return air flow path. Liquid-to-air membraneenergy exchangers (LAMEEs) may be fluidly coupled so that a desiccantliquid flows between the LAMEEs in a run-around loop, similar torun-around heat exchangers that typically use aqueous glycol as acoupling fluid.

In general, a LAMEE transfers heat and moisture between a liquid.desiccant solution and air through a thin flexible membrane. A flatplate LAMEE includes a series of alternating liquid desiccant and airchannels separated by the membrane. Typically, the pressure of theliquid within a liquid channel between membranes is higher than that ofthe air pressure outside of the membranes. As such, the flexiblemembranes tend to outwardly bow or bulge into the air channels)

In order to avoid excessive restriction of the air flow due to membranebulge, air channels of a LAMEE are relatively wide compared to theliquid channels. Moreover, a support structure is generally providedbetween membranes to limit the amount of membrane bulge. However, therelatively wide air channels and support structures typically diminishthe performance of the LAMEE. In short, resistance to heat and moisturetransfer in the air channel is relatively high due to the large airchannel width, and the support structure may block a significant amountof membrane transfer area. Accordingly, a large amount of membrane areais needed to meet performance objectives, which adds costs and resultsin a. larger LAMEE. Moreover, the support structure within an airchannel may produce an excessive pressure drop, which also adverselyaffects operating performance and efficiency of the LAMEE.

Typically, desiccant flows through a solution panel, which may includemembranes that contain the desiccant between air channels. In general,the solution panel is uniformly full of desiccant during operation.Known energy exchangers force flow of desiccant upwardly through thesolution panel, against the force of gravity. As such, the desiccant istypically pumped from the bottom of the solution panel to the top withenough pressure to overcome the relatively large amount of static headpressure, as well as the friction in the panel. However, the pumpingpressure causes the membranes of the solution panel to outwardly bow orbulge. Moreover, the pumping pressure is often great enough to causeleaks in the membranes. Further, the pressure of the desiccant beingpumped through the solution panel often causes membrane creep anddegradation over time.

A typical solution panel also includes a filler material, such as a wickor woven plastic screen, configured to ensure proper spacing betweenmembrane surfaces within the solution panel. The flow of the desiccantthrough the filler material is generally uncontrolled. For example, thefiller material is generally unable to direct the desiccant over aparticular path. Instead, the flow of desiccant through the fillermaterial follows the path of least resistance, which generally follows aHele-Shaw pattern between closed-spaced plates. Further, the flowpattern of the desiccant is sensitive to variations in the spacingwithin the solution panel caused by even small amounts of membranebulge. Also, fluid instabilities from concentration and temperaturegradients may cause additional flow irregularities andmal-distributions. The winding flow pattern within a typical solutionpanel produces flow dead zones at or proximate corners of the solutionpanel.

As noted, in order to ensure that desiccant completely fills thesolution panel from bottom to top, a relatively high pumping pressure isused. However, the pumping pressure may often generate membrane bulgeand bowing, which may adversely affect the energy exchanger.

SUMMARY OF THE DISCLOSURE

Certain embodiments of the present disclosure provide a liquid panelassembly, which may be configured to be used with an energy exchanger,for example. The liquid panel assembly may include a support framehaving one or more fluid circuits and at least one membrane secured tothe support frame. Each fluid circuit may include an inlet channelconnected to an outlet channel through one or more flow passages, suchas counterflow passages (in that liquid in the counterflow passagescounterflows with respect to another fluid, such as air, outside of theat least one membrane). A liquid, such as a desiccant, is configured toflow through the fluid circuit(s) and contact interior surfaces of themembrane(s). The fluid circuit(s) is configured to offset hydrostaticpressure gain with friction pressure loss of the liquid that flowswithin the one or more fluid circuits to reduce pressure within theliquid panel assembly.

The shape, porosity, and/or hydraulic diameter of one or both of theinlet and outlet channels may be determined by a weight, viscosity,and/or flow speed of the liquid that is configured to flow through thefluid circuit(s). For example, if the liquid is heavy, the diameters ofthe channels may be reduced in order to promote faster liquid flowtherethrough, which generates increased friction that offsets the liquidhydrostatic pressure.

The flow passages may include a set of a plurality of flow passagesconnected to the inlet channel and the outlet channel. A number of flowpassages within the set of a plurality of flow passages may hedetermined by a weight and/or viscosity of the liquid that is configuredto flow through the fluid circuit(s).

The fluid circuit(s) may include a plurality of fluid circuits. Thelengths of each of the fluid circuits may be equal. The plurality offluid circuits may include a first set of a plurality of flow passagesconnected to a first inlet channel and a first outlet channel, and asecond set of a plurality of flow passages connected to a second inletchannel and a second outlet channel. The first set of a plurality offlow passages may be staggered with respect to the second set of aplurality of flow passages.

Each of the inlet and outlet channels may provide a flow alignment vaneconfigured to direct the liquid to flow along a particular path. Theinlet and outlet channels may be configured to provide support to themembrane(s). The inlet and outlet channels may be configured to providea sealing surface for at least a portion of the membrane(s). The inletand outlet channels may be configured to maximize a length of the flowpassages.

The membrane(s) may be continuously bonded around a perimeter of thesupport frame. The fluid circuits may be configured to provide uniformliquid flow distribution across and/or through the liquid panelassembly. The support frame and the membrane may be configured to bevertically oriented within an energy exchange cavity of an energyexchanger.

The inlet channel may be disposed at an upper corner of the supportframe. The outlet channel may be disposed at a lower corner of thesupport frame. The upper corner may be diagonally located from the lowercorner. The inlet and, outlet channels may be vertical and the flowpassages(s) may be horizontal. A horizontal length of the flowpassage(s) may exceed half a total horizontal length of the supportframe. The assembly may also include inlet and outlet members, such asheaders, connected to the fluid circuit(s). The inlet and outlet membersmay include a liquid delivery channel and a liquid passage channel,respectively. The inlet member may be configured to modularly engageanother inlet member, and the outlet member may be configured tomodularly engage another outlet member. At least a portion of themembrane(s) may sealingly engage the inlet and outlet members.

Alternatively, the support frame and the membrane may be configured tobe horizontally oriented within an energy exchange cavity of an energyexchanger,

The inlet channel may be disposed at one corner of the support frame.The outlet channel may be disposed at another corner of the supportframe. The first corner may be diagonally located from the secondcorner. The inlet and outlet channels may be vertical and the flowpassages(s) may be horizontal. A horizontal length of the flowpassage(s) may exceed half a total horizontal length of the supportframe.

The assembly may also include inlet and outlet members, such as headers,connected to the fluid circuit(s). The inlet member may fluidly engageall inlet channels and the outlet member may fluidly engage all outletchannels.

Alternatively, the flow passages in one or more panels can be fluidlyconnected to members, such as headers. One or more of these members canbe fluidly connected to flow channels. Inlet channels can be fluidlyconnected to inlet members which can, in turn, be connected to flowpassages. The flow passages can be fluidly connected to outlet members,such as headers, which are, in turn, connected to outlet channels.

Certain embodiments of the present disclosure provide an energy exchangesystem that may include a plurality of air channels configured to allowair to pass therethrough, and a plurality of liquid panel assembliesalternately spaced with the plurality of liquid panel assemblies. Thesystem may also include a plurality of membrane support assembliesdisposed within the plurality of air channels. Air within the airchannels may be configured to counterflow with respect to the liquidwithin the one or more flow passages.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a schematic view of an energy exchange system.,according to an embodiment of the present disclosure.

FIG. 2 illustrates a side perspective view of a liquid-to-air membraneenergy exchanger, according to an embodiment of the present disclosure.

FIG. 3 illustrates a cut-away front view of panels within an energyexchange cavity of a liquid-to-air membrane energy exchanger, accordingto an embodiment of the present disclosure.

FIG. 4 illustrates an exploded isometric top view of an energy exchangecavity, according to an embodiment of the present disclosure.

FIG. 5 illustrates a front view of a support frame of a liquid panelassembly, according to an embodiment of the present disclosure.

FIG. 6 illustrates an isometric top view of an inlet member, accordingto an embodiment of the present disclosure,

FIG. 7 illustrates an internal view of an inlet member, according to anembodiment of the present disclosure.

FIG. 8 illustrates an isometric view of an area proximate an uppercorner of a support frame of a liquid panel assembly, according to anembodiment of the present disclosure.

FIG. 9 illustrates a chart of fluid pressure levels within a liquidpanel assembly, according to an embodiment of the present disclosure.

FIG. 10 illustrates a front view of a support frame of a liquid panelassembly, according to an embodiment of the present disclosure.

FIG. 11 illustrates an isometric top view of liquid distributionChannels formed in a support frame, according to an embodiment of thepresent disclosure.

FIG. 12 illustrates an isometric top view of liquid distributionchannels formed in a support frame, according to an embodiment of thepresent disclosure.

FIG. 13 illustrates a simplified view of a liquid circuit, according toan embodiment of the present disclosure.

FIG. 14 illustrates a simplified view of a liquid circuit, according toan embodiment of the present disclosure.

FIG. 15 illustrates a simplified view of a liquid circuit, according toan embodiment of the present disclosure.

FIG. 16 illustrates an isometric view of horizontal liquid panelassemblies connected to combined inlet channels and combined outletchannels, according to an embodiment of the present disclosure.

FIG. 17 illustrates an isometric view of horizontal liquid panelassemblies connected to individual inlet channels and individual outletchannels, according to an embodiment of the present disclosure.

FIG. 18 illustrates an isometric view of stacked horizontal liquid panelassemblies connected to inlet headers, according to an embodiment of thepresent disclosure.

FIG. 19 illustrates an isometric view of stacked horizontal liquid panelassemblies with external pressure balancing, according to an embodimentof the present disclosure.

DETAILED DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofcertain embodiments will be better understood when read in conjunctionwith the appended drawings. As used herein, an element or step recitedin the singular and proceeded with the word “a” or “an” should beunderstood as not excluding plural of said elements or steps, unlesssuch exclusion is explicitly stated. Furthermore, references to “oneembodiment” are not intended to be interpreted as excluding theexistence of additional embodiments that also incorporate the recitedfeatures. Moreover, unless explicitly stated to the contrary,embodiments “comprising” or “having” an element or a plurality ofelements having a particular property may include additional suchelements not having that property.

As explained in detail below, embodiments of the present disclosureprovide liquid panel assemblies that are configured to balance internalliquid hydrostatic pressure and frictional forces. As such, the totalpressure within the liquid panel assemblies may be reduced, negated orotherwise neutralized. Embodiments of the present disclosure provide aliquid panel assembly that may be configured, through selection of anumber, orientation, shape, and/or the like of flow channels orpassages, to ensure that pressure within the assembly is substantiallyreduced, negated, or otherwise neutralized. That is, the pressure may bereduced, negated, or otherwise neutralized to a greater extent than anegligible amount. Thus, membrane bulge is substantially reduced (thatis, more than a negligible amount) or eliminated, which reduces thepotential for leaks and membrane creep.

FIG. 1 illustrates a schematic view of an energy exchange system 100,according to an embodiment of the present disclosure. The system 100 isconfigured to partly or fully condition air supplied to a structure 101.The system 100 may include an inlet 102 for a pre-conditioned air flowpath 104. The pre-conditioned air flow path 104 may include outside air,air from a building adjacent to the enclosed structure 101, or air froma room within the enclosed structure 101. Airflow in the pre-conditionedair flow path 104 may be moved through the pre-conditioned air flow path104 by a fan 106. The fan 106 directs the pre-conditioned air flowthrough path 104 to a supply air liquid-to-air membrane energy exchanger(LAMEE) 108. The supply air LAMEE 108 conditions the pre-conditioned airflow in path 104 to generate a change in air temperature and humidity(i.e. to pre-conditioned the air partly or fully) toward that which isrequired for a supply air flow condition to be discharged into theenclosed space 101. During a winter mode operation, the supply air LAMEE108 may condition the pre-conditioned air flow path 104 by adding heatand moisture to the pre-conditioned air in flow path 104. In a summermode operation, the supply air LAMEE 108 may condition thepre-conditioned air flow path 104 by removing heat and moisture from thepre-conditioned air in flow path 104. The pre-conditioned air 110 may bechanneled to an HVAC system 112 of the enclosed structure 101. The HVACsystem 112 may further condition the pre-conditioned air 110 to generatethe desired temperature and humidity for the supply air 114 that issupplied to the enclosed structure 101.

As shown in FIG. 1 , one fan 106 may be located upstream of the LAMEE108. Optionally, the pre-conditioned air flow path 104 may be moved by adown-stream fan and/or by multiple fans or a fan array or before andafter each LAMEE in the system.

Return air 116 is channeled out of the enclosed structure 101. A massflow rate portion 118 of the return air 116 may be returned to the HVACsystem 112. Another mass flow rate portion 119 of the return air 116 maybe channeled to a return air or regeneration LAMEE 120. The portions 118and 119 may be separated with a damper 121 or the like. For example, 80%of the return air 116 may be channeled to the HVAC system 112 and 20% ofthe return air 116 may be channeled to the return air LAMEE 120. Thereturn air LAMEE 120 exchanges energy between the portion 119 of thereturn air 116 and the preconditioned air 110 in the supply air LAMEE108. During a winter mode, the return air LAMEE 120 collects heat andmoisture from the portion 119 of the return air 116. During a summermode, the return air LAMEE 120 discharges heat and moisture into theportion 119 of the return air 116. The return air LAMEE 120 generatesexhaust air 122. The exhaust air 122 is discharged from the structure101 through an outlet 124. A fan 126 may be provided to move the exhaustair 122 from the return air LAMEE 120. The system 100 may includemultiple fans 126 or one or more fan arrays located either up-stream ordown-stream (as in FIG. 1 ) of the return air LAMEE 120.

A liquid, such as a desiccant fluid 127, flows between the supply airLAMEE 108 and the return air LAMEE 120. The desiccant fluid 127transfers the heat and moisture between the supply air LAMEE 108 and thereturn air LAMEE 120. The system 100 may include desiccant storage tanks128 in fluid communication between the supply air LAMEE 108 and thereturn air LAMEE 120. The storage tanks 128 store the desiccant fluid127 as it is channeled between the supply air LAMEE 108 and the returnair LAMEE 120. Optionally, the system 100 may not include both storagetanks 128 or may have more than two storage tanks. Pumps 130 areprovided to move the desiccant fluid 127 from the storage tanks 128 toone of the supply air LAMEE 108 or the return air LAMEE 120. Theillustrated embodiment includes two pumps 130. Optionally, the system100 may be configured with as few as one pump 130 or more than two pumps130. The desiccant fluid 127 flows between the supply air LAMEE 108 andthe return air LAMEE 120 to transfer heat and moisture between theconditioned air 110 and the portion 118 of the return air 116.

FIG. 2 illustrates a side perspective view of a LAMEE 300. according toan embodiment. The LAMEE 300 may be used as the supply air LAMEE 108and/or the return or exhaust air LAMEE 120 (shown in FIG. 1 ). The LAMEE300 includes a housing 302 having a body 304. The body 304 includes anair inlet end 306 and an air outlet end 308. A top 310 extends betweenthe air inlet end 306 and the air outlet end 308. While note shown, astepped-down top may be positioned at the air inlet end 306. Thestepped-down top may be stepped a distance from the top 310. A bottom316 extends between the air inlet end 306 and the air outlet end 308.While not shown, a stepped-up bottom may be positioned at the air outletend 308. The stepped-up bottom may be stepped a distance from the bottom316. In alternative designs the stepped-up bottom or stepped-down topsections may have different sizes of steps or no step at all

An air inlet 322 is positioned at the air inlet end 306. An air outlet324 is positioned at the air outlet end 308. Sides 326 extend betweenthe air inlet 322 and the air outlet 324.

An energy exchange cavity 330 extends through the housing 302 of theLAMEE 300. The energy exchange cavity 330 extends from the air inlet end306 to the air outlet end 308. An air stream 332 is received in the airinlet 322. and flows through the energy exchange cavity 330. The airstream 332 is discharged from the energy exchange cavity 330 at the airoutlet 324. The energy exchange cavity 330 may include a plurality ofpanels 334. such as liquid panels configured to receive desiccant anddirect the flow of the desiccant therethrough.

A desiccant inlet reservoir 352 may be positioned on the top 310. Thedesiccant inlet reservoir 352 may be configured to receive desiccant,which may be stored in a storage tank 128 (shown in FIG. 1 ). Thedesiccant inlet reservoir 352 may include an inlet in flow communicationwith the storage tank 128. The desiccant is received through the inlet.The desiccant inlet reservoir 352 may also include an outlet that is influid communication with desiccant channels 376 of the panels 334 in theenergy exchange cavity 330. The liquid desiccant flows through theoutlet into the desiccant channels 376. The desiccant flows along thepanels 334 through the desiccant channels 376 to a desiccant outletreservoir 354, which may be positioned at or proximate the bottom 316.Accordingly, the desiccant may flow through the LAMEE 300 from top tobottom. For example, the desiccant may flow into the desiccant channels376 proximate the desiccant inlet reservoir 352, through the desiccantchannels 376, and out of the LAMEE 300 proximate to the desiccant outletreservoir 354. In an alternative embodiment, the desiccant may flowthrough the LAMEE 300 from bottom to top.

FIG. 3 illustrates a cut-away front view of the panels 334 within theenergy exchange cavity 330 of the LAMEE 300, according to an embodiment.The panels 334 may be solution or liquid panels configured to direct theflow of liquid, such as desiccant, therethrough, as explained below. Thepanels 334 form a liquid desiccant flow path 376 that is confined bysemi-permeable membranes 378 on either side and is configured to carrydesiccant therethrough. The membranes 378 may or may not be porous orable to transfer mass. Each membrane 378 may be any flexible structurethat may generally bulge under fluid pressure. The semi-permeablemembranes 378 are arranged in parallel to form air channels 336 with anaverage flow channel width of 337 and liquid desiccant channels 376 withan average flow channel width of 377. In one embodiment, thesemi-permeable membranes 378 are spaced to form uniform air channels 336and liquid desiccant channels 376. The air stream 332 (shown in FIG. 2 )travels through the air channels 336 between the semi-permeablemembranes 378. The desiccant in each desiccant channel 376 exchangesheat and moisture with the air stream 332 in the air channels 336through the semi-permeable membranes 378. The air channels 336 alternatewith the liquid desiccant channels 376. Except for the two side panelsof the energy exchange cavity, each air channel 336 may be positionedbetween adjacent liquid desiccant channels 376.

In order to minimize or otherwise eliminate the liquid desiccantchannels 376 from outwardly bulging or bowing, membrane supportassemblies may be positioned within the air channels 336. The membranesupport assemblies are configured to support the membranes, and maypromote turbulent air flow between the air channels 336 and themembranes 378.

As an example, the LAMEE 300 may be similar to a LAMEE as described inWO 2011/161547, entitled “Liquid-To-Air Membrane Energy Exchanger,”filed Jun. 22, 2011, which is hereby incorporated by reference in itsentirety.

FIG. 4 illustrates an exploded isometric top view of an energy exchangecavity 400, according to an embodiment. The energy exchange cavity 400may include a plurality of liquid panel assemblies 402 spaced apart fromone another by membrane support assemblies 404, such as those describedin U.S. patent application Ser. No. 13/797,062, entitled “MembraneSupport Assembly for an Energy Exchanger,” filed Mar. 12, 2013, whichclaims priority to U.S. Provisional Application No. 61/692,793, entitled“Membrane Support Assembly for an Energy Exchanger,” filed Aug. 24,2012, both of which are hereby incorporated by reference in theirentireties. The membrane support assemblies 404 may reside in airchannels 406. For example, the membrane support assemblies 404 mayprevent membranes 418 of the solution panel assemblies 402 fromoutwardly bulging or bowing into the air channels 406. Airflow 408 isconfigured to pass through the air channels 406 between liquid panelassemblies 402. As shown, the airflow 408 may generally be aligned witha horizontal axis 410 of the energy exchange cavity 400. Thus, theairflow 408 may be horizontal with respect to the energy exchange cavity400. Notably, however, the membrane support assemblies 404 may includeturbulence promoters configured to generate turbulence, eddies, and thelike in the airflow 408 within the energy exchange cavity 400.

Each liquid panel assembly 402 may include a support frame 412 connectedto an inlet member 414 at an upper corner 415 and an outlet member 416at a lower corner 417 that may be diagonal to the upper corner 415.Further, membranes 418 are positioned on each side of the support frame412. The membranes 418 are formed of a liquid impermeable, but airpermeable, material. The membranes 418 sealingly engage the supportframe 412 along outer edges in order to contain liquid within the liquidpanel assembly 402. Alternatively, a single membrane may sealingly wraparound an entirety of the support frame 412.

Each inlet member 414 may include a liquid delivery opening 420, whileeach outlet member 416 may include a liquid passage opening 422. Theliquid delivery openings 420 may be connected together through conduits,pipes, or the like, while the liquid passage openings 422 may beconnected together through conduits, pipes, or the like. Optionally, theinlet members 414 and outlet members 416 may be sized and shaped todirectly mate with one another so that a liquid-tight seal is formedtherebetween. Accordingly, liquid, such as desiccant may flow throughthe liquid delivery openings 420 and the liquid passage openings 422.The inlet members 414 and outlet members 416 may he modular componentsconfigured to selectively couple and decouple from other inlet members414 and outlet members 416, respectively. For example, the inlet members414 and outlet members 416 may be configured to securely mate with otherinlet members 414 and outlet members 416, respectively, through snapand/or latthing connections, or through fasteners and adhesives.

As shown, the liquid panel assemblies 402, the membrane supportassemblies 404, and the air channels 406 may all be vertically oriented.The liquid panel assemblies 402 may be flat plate exchangers that arevertically-oriented with respect to a base that is supported by a floor,for example, of a structure.

Alternatively, the liquid panel assemblies 402, the membrane supportassemblies 404, and the air channels 406 may all be horizontallyoriented. For example, the liquid panel assemblies 402 may be flat plateexchangers that are horizontally-oriented with respect to a base that issupported by a floor, for example, of a structure.

In operation, liquid, such as desiccant, flows into the liquid deliveryopenings 420 of the inlet members 414. For example, the liquid may bepumped into the liquid delivery openings 420 through a pump. The liquidthen flows into the support frames 412 through a liquid path 424 towardthe outlet members 416. As shown, the liquid path 424 includes avertical descent 426 that connects to a horizontal, flow portion, suchas a flow portion 428, which, in turn, connects to a vertical descent430 that connects to the liquid passage opening 422 of the outlet member416. The vertical descents 426 and 430 may be perpendicular to thehorizontal, flow portion 428. As such, the liquid flows through thesolution panel assemblies 402 from the top corners 415 to the lowercorners 417. As shown, the length of the horizontal, flow portion 428substantially exceeds half the length L of the liquid panel assemblies402. The horizontal, flow portion 428 provides liquid, such asdesiccant, that may counterflow with respect to the airflow 408.Alternatively, the flow portion may be a crossflow, parallel-alignedflow, or other such flow portion, for example.

The airflow 408 that passes between the liquid panel assemblies 402exchanges energy with the liquid flowing through the liquid panelassemblies 402. The liquid may be a desiccant, refrigerant, or any othertype of liquid that may be used to exchange energy with the airflow 408.

The energy exchange cavity 400 may include more or less liquid panelassemblies 402, membrane support assemblies 404, and air channels 406than those shown in FIG. 4 . The inlet and outlet members 414 and 416may be modular panel headers that are configured to selectively attachand detach from neighboring inlet and outlet members 414 and 416 toprovide a manifold for liquid to enter into and pass out of the liquidpanel assemblies 402. Sealing agents, such as gaskets, silicone gel, orthe like, may be disposed between neighboring inlet members 414 andneighboring outlet members 416. At least a portion of the membranesealingly engages the inlet and outlet members 414 and 416. The liquidpanel assembly 402 formed in this manner provides a fully-sealed,stand-alone unit having openings at the inlet and outlet members 414 and416, notably the openings 420 and 422, respectively. Accordingly, theliquid panel assembly 402 may be pre-tested for leaks and membrane holesprior to being positioned within an energy exchange cavity, for example.

FIG. 5 illustrates a front view of the support frame 412 of the liquidpanel assembly 400, according to an embodiment. For the sake of clarity,the membranes 418 secured to the liquid panel assembly 400 are notshown. However, it is to be understood that at least one membrane 418 isbonded to the front and back surfaces of the support frame 412. Forexample, the membrane 418 may be continuously bonded around theperimeter of the support frame 412, thereby creating a robust externalseal.

The support frame 412 includes a main body 438 having a lower edge 440connected to an upper edge 442 through lateral edges 444. The supportframe 412 may be formed of various materials, such as injection moldedplastic, metal, or a combination thereof. The support frame 412 may beintegrally formed and manufactured as a single piece through a singlemolding process, for example. For example, the inlet and outlet members414 and 416, respectively, may be integrally molded with the supportframe 412. Optionally, the support frame 412 may be formed as separateand distinct pieces. For example, the support frame 412. may be extrudedand assembled from various parts.

The inlet member 414 includes a base 446 that connects to a supportinlet 448 proximate the upper corner 415. The upper corner 415 mayinclude a channel configured to receive and retain the base 446. Forexample, the base 446 may fit into the channel and be securely fastenedtherein, such as through fasteners, adhesives, or the like. Optionally,as noted above, the base 446 may simply be integrally formed and moldedwith the upper corner 415. The base 446 supports and connects to anupper wall 449 through lateral walls 450. The base 446, the upper wall449, and the lateral walls 450 define the liquid-delivery opening 420.Liquid passages (hidden from view in FIG. 5 ) are formed through thebase 446 and connect the liquid-delivery opening 420 to aliquid-reception area 452 formed at the upper corner 415 of the supportframe 412.

FIG. 6 illustrates an isometric top view of the inlet member 414,according to an embodiment. As shown, a lower edge 460 of the base 446may be tapered or beveled, which allows the base 446 to be easily matedinto a reciprocal channel of the support inlet 448 (shown in FIG. 5 ).An opening 462 is formed at a terminal end of the beveled lower edge460. The opening 462 connects to liquid passages (hidden from view inFIG. 6 ) that connect to an opening (hidden from view in FIG. 6 ) thatconnects to the liquid delivery opening 420. Accordingly, liquid maypass from the liquid delivery opening 420, out through the opening 462of the base 446 and into the support inlet 448 of the support frame 412.

FIG. 7 illustrates an internal view of the inlet member 414, accordingto an embodiment. As shown in FIG. 7 , the opening 462 is incommunication with a plurality of liquid passages 470 separated by guideribs 472. The liquid passages 470 are configured to align with liquidinlet channels of the support frame 412. While eight liquid passages 470are shown in FIG. 7 , more or less liquid passages 470 may be used,depending on the number of liquid inlet channels of the support, frame412.

Referring again to FIG. 5 , the outlet member 416 is similarlyconstructed to the inlet member 414. The inlet and outlet members 414and 416 are both liquid connection members configured to deliver and/orpass liquid to and/or from the support, frame 412. Accordingly, similarto the inlet member 414, the outlet member 416 includes a base 446 thatconnects to a support outlet 480 of the support member 412 proximate thelower corner 417. The lower corner 417 may include a channel configuredto receive and retain the base 446. For example, the base 446 may fitinto the channel and be securely fastened therein, such as throughfasteners, adhesives, or the like. Optionally, as noted above, the base446 may simply be integrally formed and molded with the lower corner417. The base 446 supports and connects to an upper wall 449 throughlateral walls 450. The base 446, the upper wall 449, and the lateralwalls 450 define the liquid-delivery opening 422. Liquid passages(hidden from view in FIG. 5 ) are formed through the base 446 andconnect the liquid-delivery opening 422 to a liquid-passage area 482formed at the lower corner 417 of the support frame 412. The outletmember 416 may be constructed as shown in FIGS. 6 and 7 .

The inlet and outlet members 414 and 416 provide panel headers that areconfigured to provide passageways for liquid, such as desiccant, to passinto and out of the liquid panel assembly 402. The inlet and outletmembers 414 and 416 may also provide mating surfaces to neighboringpanels to create a manifold to distribute liquid to all solution panelswithin an energy exchanger.

FIG. 8 illustrates an isometric view of an area proximate the uppercorner 415 of the support frame 412 of the liquid panel assembly 402.Referring to FIGS. 5 and 8 , the support frame 412 includes verticalinlet channels 490 connected to vertical outlet channels 492 throughhorizontal flow passages 494. As shown, the support frame 412 mayinclude eight vertical inlet channels 490 and eight vertical outletchannels 492. However, the support frame 112 may include more or lessinlet and outlet channels 490 and 492 than those shown. Each inletchannel 490 may connect to five horizontal flow passages 191. Forexample, the innermost inlet channel 490 a connects to the top fivehorizontal flow passages 494 a. Similarly, the inlet channel 490 bconnects to the five horizontal flow passages 494 below the top fivehorizontal flow passages 494 a. Similarly, the top five flow passages494 a connect to an outermost vertical outlet channel 492 a.Accordingly, the horizontal flow passages 494 may be staggered in setsof five with respect to the support frame 412. For example, inlet ends498 of the horizontal flow passages 494 a are farther away from thelateral edge 444 a of the support frame 412 than the inlet ends 498 ofthe set of horizontal flow passages 494 immediately below the set ofhorizontal flow passages 494 a. However, outlet ends 500 of thehorizontal flow passages 494 a are closer to the lateral edge 444 b ofthe support frame 412 than the outlet ends 500 of the set of horizontalflow passages 494 immediately below the set of horizontal flow passages494 a. Further, the length of the inlet channel 490 a is shorter thanthe length of the inlet channel 490 b adjacent the inlet channel 490 a.The length of the inlet channel 490 b is longer in order to connect tothe set of five horizontal flow passages 494 underneath the set of fivehorizontal flow passages 494 a. Conversely, the length of the verticaloutlet channel 492 a is longer than the length of the vertical outletchannel 492 b immediately adjacent the vertical distribution channel 492a.

The vertical inlet and outlet channels 490 and 492, respectively,provide continuous flow alignment vanes. Each channel 490 and 492 may bean isolated duct that allows the pressure of liquid in neighboringchannels 490 and 492 to vary in order to evenly split the flow of liquidamong the channels 490 and 492. As noted, each vertical distribution andpassage channel 490 and 492 may feed a single horizontal flow passage494, or a set or bank of horizontal flow passages 494. The membrane 418(shown in FIG. 4 ) may also be bonded to internal edge surfaces of thesupport frame 412 to separate each vertical channel 490 and 492 from oneanother, as well as to separate each horizontal flow passage 494 fromone another. Therefore, each fluid circuit, which includes an inletchannel 490, one or more flow passages 494, and an outlet channel 492,may be a separate, sealed duct.

Each of the inlet and outlet channels 490 and 492 may provide a flowalignment vane configured to direct liquid to flow along a particularpath. The inlet and outlet channels 490 and 492 may be configured toprovide support to the membrane. The inlet and outlet channels may beconfigured to provide a sealing surface for at least a portion of themembrane.

As shown in FIGS. 5 and 6 , the horizontal flow passages 494 are groupedin sets of five, which are staggered with respect to one another. Thesets of horizontal flow passages 494 are staggered so that the overalllength of each horizontal flow passage 494 is the same. Indeed, thetotal length of each liquid circuit, which includes a vertical inletchannel 490 that connects to a horizontal flow passage 494, which inturn connects to a vertical outlet channel 492, is the same due to thestaggered nature of the sets of horizontal flow passages 494 and thedifferent lengths of each of the vertical inlet channels 490 and thevertical outlet channels 492. The total vertical height H of a liquidcircuit is the length of a vertical inlet channel 490 plus the length ofa vertical outlet channel 492 that connects to the vertical inletchannel 490 through a horizontal flow passage 494. The vertical inletchannel 490 a is the shortest, while the vertical outlet channel 492 a(which connects to the inlet channel 490 a through the fluid passages494 a) is the longest. Conversely, the vertical inlet channel 490 n isthe longest, while the vertical outlet channel 492 n (which connects tothe inlet channel 490 n through the fluid passages 494 n) is theshortest. Further, the length of the vertical inlet channel 490 a mayequal the length of the vertical outlet channel 492 n, while the lengthof the vertical inlet channel 490 n may equal the length of the verticaloutlet channel 492 a. In short, the total vertical lengths for eachliquid circuit may sum to H. Moreover, the total length of each liquidcircuit, which includes a vertical inlet channel 490 that connects to avertical outlet channel 492 through a horizontal fluid passage 494, maybe equal,

While particular inlet and outlet channels 490 and 492, respectively,are each shown connecting to a set of five horizontal fluid passages494, the inlet and outlet channels 490 and 492, respectively, mayconnect to more or less than five horizontal fluid passages 494. Forexample, the sets of horizontal fluid passages 491 may be two, three,six, seven, and the like. Further, each distribution and passage channel490 and 492, respectively, may alternatively connect to only onehorizontal fluid passage 494.

The liquid circuits are of equal length in order to provide for evendistribution of liquid flow through the liquid panel assembly 402. Theliquid panel assembly 402 is configured to operate at low pressure. Thatis, the liquid panel assembly 402 provides a low pressure assembly. Theliquid that flows through the liquid panel assembly 402 has a particularweight and viscosity. For example, a desiccant is a dense fluid. Theweight of the liquid creates fluid pressure. As the liquid flows fromthe top of the liquid panel assembly 402 to the bottom, the pressurefrom the weight of the liquid builds. As the liquid moves through theliquid panel assembly 402, the pressure is reduced through friction, forexample. For example, the faster the speed of the liquid within a liquidcircuit, the greater the friction between the liquid and walls ofchannels and passages that define the liquid circuit. Therefore,increasing the speed of the liquid, such as through pumping, increasesthe frictional force. Embodiments of the present disclosure provide aliquid panel assembly that balances the loss of pressure from frictionwith the pressure of the weight of the liquid.

The friction head loss, h_(f), of a fluid flowing in a channel of lengthL is given by the following:

$\frac{h_{f}}{L} = \frac{C\mu V}{2g\rho D_{h}^{2}}$

where C is a coefficient that depends on the duct geometry (and may alsobe used to represent the friction of porous material in the duct), μ isthe molecular viscosity of the fluid, V is the bulk speed of the fluidin the duct, g is the acceleration due to gravity, p is the density ofthe fluid, and D_(h) is the hydraulic diameter of the duct. The frictionhead loss may be synonymous with pressure drop (“head” refers to theheight of a column of fluid that would produce the pressure), that is,ΔP=pgh_(f).

Embodiments of the present disclosure provide a liquid panel assembly inwhich friction head loss may be the same or approximately the same as adrop in vertical elevation of the fluid as it flows downward in thechannels, due to the gain in static pressure, which is given by ΔP=pgΔz,where Δz is the drop in vertical elevation (in the direction ofgravity). Therefore, adding the two pressure changes together givesΔP_(net)=pg(Δz-h_(f)). A closely balanced flow with low pressure wouldhave Δz≈h_(f). Embodiments of the present disclosure provide pressurebalancing channels at the ends of the panel that are orientedvertically, therefore, Δz=L. As such, the following may he consultedwhen selecting the size, shape, orientation, and the like of the fluidcircuits:

$\frac{h_{f}}{L} = {\frac{C\mu V}{2g\rho D_{h}^{2}} \approx 1}$

However, complete balance as shown in the above equation is notnecessarily required. Instead, the gauge pressure may be kept low enoughto meet structural limitations of the membrane and support design(keeping membrane strain and stress within acceptable limits).

In an example, the weight of the liquid produces pressure in thevertical inlet and outlet channels 490 and 492, respectively. However,it has been found that increasing the number of horizontal fluidpassages 494 connecting to particular inlet and outlet channels 490 and492 increases the rate of fluid flow within the vertical inlet andoutlet channels 490 and 492, respectively. Fluid velocity is directlyproportional to friction. Thus, with increased fluid velocity, frictionincreases. The friction diminishes the overall pressure of the liquidwithin the liquid panel assembly 402. Therefore, by increasing thefriction of the fluid with the walls of the channels and passages of theliquid panel assembly 402, the pressure is reduced. As an example, ithas been found that connecting single vertical inlet and outlet channels490 and 492, respectively, to sets of four or five horizontal fluidpassages 494 may substantially or completely offset the pressure causedby the weight of a desiccant. Because different liquids have differentdensities and weights, the liquid panel assembly 402 may be configuredto account for the differences in densities and weights. For example,the sets of horizontal flow passages 494 may he smaller, such as set of2 or 3, for lighter liquids, than for heavier liquids. Therefore, anumber of flow passages 494 within a set of multiple flow passages 491connected to individual channels 490 and 492 may be based on and/ordetermined by a weight of the liquid that is configured to flow throughfluid circuits that include the sets of liquid passages and channels 490and 492. In general, embodiments of the present disclosure areconfigured to offset hydrostatic pressure gain of the liquid withfriction pressure loss of the flowing liquid within one or more fluidcircuits to minimize or eliminate pressure within a liquid panelassembly.

Additionally, the hydraulic diameters of the inlet and outlet channels490 and 492, as well as the hydraulic diameters of the horizontal fluidpassages 494, may be adjusted to balance liquid hydrostatic pressurewith friction. For example, the hydraulic diameter of each channel orpassage may be directly proportional to the velocity of liquid flowingtherethrough. Thus, decreasing the hydraulic diameter of the channel orpassage leads to an increased velocity of pumped liquid therethrough. Asnoted, increasing liquid velocity increases friction, which reduces thenet pressure. Therefore, the hydraulic diameter of the channels 490 and492 may be based on and/or determined, in part, by a weight of theliquid that is configured to flow through fluid circuits that includethe channels 490 and 492. In addition to the number of horizontal flowpassages 494 in a set that connect to individual vertical inlet andoutlet channels 490 and 492, respectively, the hydraulic diameter of thechannels 490 and 492, as well as the flow passages 494 may be sized andshaped to generate a desired friction with respect to a particularliquid.

Thus, the liquid panel assembly 402 includes liquid circuits that areconfigured to balance the force of liquid hydrostatic pressure andfriction by adjusting the number of horizontal flow passages 494 thatconnect to the vertical inlet and outlet channels 490 and 492,respectively, and/or the hydraulic diameter of the channels and/orpassages, in order to reduce the net pressure within the liquid. panelassembly 402.

The hydraulic diameters of the horizontal fluid passages 494 may berelatively wide compared to the vertical inlet and outlet channels 490and 492, respectively. As such, the friction in relation to the liquidin the horizontal fluid passages 494 may be relatively small compared tothe vertical inlet and outlet channels 490 and 492, respectively. Thepressure drop in the horizontal fluid passages 494 may be relativelysmall. Because less friction in the horizontal flow passages 494 may bedesired, the hydraulic diameters of the flow passages 494 may be widerthan the hydraulic diameters of the vertical inlet and outlet channels490 and 492, respectively. Therefore, the balancing of liquidhydrostatic pressure and friction may be achieved through the velocityof liquid through the vertical inlet and/or outlet channels 490 and 492,respectively, which may be controlled through the number of horizontalflow passages 494 connecting to each channel 490 and 492, and/or thehydraulic diameters of the channels 490 and 492.

Referring to FIGS. 4, 5, and 8 , the lengths of the horizontal flowpassages 494 may be substantially longer than half the length L of thesupport frame 412. Indeed, the lengths of the horizontal flow passagesmay be almost as long as the length L of the support frame 412. Forexample, the horizontal flow passages 494 may be the length of thesupport frame 412 minus the horizontal area occupied by the inlet andoutlet channels 490 and 492, respectively. Accordingly, each fluidcircuit may have a substantial length along a horizontal orientation.The linear, horizontal distances of the horizontal flow passages 494increase the efficiency of energy exchange between the liquid flowingtherethrough, and the airflow on either side of the membranes of thesolution panel assemblies 402. As shown in FIG. 5 , the horizontal flowpassages 494 increase the flow of liquid in the horizontal direction sothat the direction of liquid flow D_(L) is counter to the direction ofairflow D_(A). It has been found that increasing the distance ofcounterflow between the liquid in the fluid circuits and the airflowincreases the efficiency of energy exchange therebetween. A counterflowarrangement of the air and liquid streams provides an efficient andhighly effective energy exchanger. The horizontal flow passages 494maximize the counterflow area, and allow the liquid to distributeevenly. As noted above, however, the flow passages 494 may bealternatively be configured to provide crossflow, parallel-aligned flow,or other such flow.

FIG. 9 illustrates a chart of fluid pressure levels within a liquidpanel assembly 402, according to an embodiment. As shown in FIG. 9 , thepressure level of liquid through an inlet length L_(i) (over the lengthof the vertical inlet channel 490) increases until the liquid passesinto the horizontal flow passage 494, through which the pressure levelL_(C) remains constant. The pressure of the liquid in the verticaloutlet channel 492 increases. However, as shown in FIG. 9 , the frictionof the liquid with respect to the liquid panel assembly 402 offsets thepressure levels of the liquid. As such, the pressure force 902 of theliquid is offset by the frictional force 904, thereby yielding a neutralpressure 906 within the liquid panel assembly 402. The vertical inletand outlet channels 490 and 492, respectively, may be consideredfriction control members that are used to balance the pressure withinthe liquid panel assembly 402.

FIG. 10 illustrates a front view of a support frame 1000 of a liquidpanel assembly 1002, according to an embodiment. The support frame 1000may include end sections 1004 and 1006 and an intermediate body 1008.The end section 1004 may provide vertical inlet channels 1010, while theend section 1006 may provide vertical outlet channels 1012, or viceversa. The intermediate body 1008 may provide horizontal flow passages1014. The intermediate body 1008 includes flow passage sets 1016-1030that are staggered and/or offset with one another with respect to avertical axis 1040 of the intermediate body 1008. Each of the endsections 1004 and 1006, as well as the intermediate body 1008 may beformed from extruded parts and assembled together, such as throughfasteners, bonding, and the like. The end sections 1004, 1006, and theintermediate body 1008 may be formed by extruding a flat sheet ofplastic or metal, and then embossing the channel shapes using groovedrollers, for example.

Alternatively, any of the liquid panel assemblies described above may beformed through injection molding either as separate sub-parts that arelater bonded together, or as a single, unitary piece. Injection moldingthe liquid panel assembly as a single piece, for example, eliminates thepotential for joint failure or leakage at bonded seams.

FIG. 11 illustrates an isometric top view of liquid inlet channels 1100formed in a support frame 1102, according to an embodiment. As shown,the inlet channels 1100 may be grooves formed between ridges 1104 in thesupport frame 1102. The liquid outlet channels may be formed in asimilar manner.

FIG. 12 illustrates an isometric top view of liquid inlet channels 1200formed in a support frame 1202, according to an embodiment. In thisembodiment, the inlet channels 1200 may be cut completely through thesupport frame 1202, thereby forming a planar channel through the supportframe 1202. The liquid outlet channels may be formed in a similarmanner.

Referring to FIGS. 4-12 , as explained above, the inlet channels and theoutlet channels of the support frame may be vertical and linear, whilethe flow passages may be horizontal and linear. It has been found thatthe linear vertical and horizontal configuration of each liquid circuitprovides for efficient pressure balancing within the solution panelassemblies. However, the liquid circuits may be various other shapes andsizes. As discussed above, a liquid circuit may include a vertical inletchannel, one or a set of horizontal flow passages, and a vertical outletchannel.

FIG. 13 illustrates a simplified view of a liquid circuit 1300,according to an embodiment. The liquid circuit 1300 includes a verticalinlet channel 1302 connected to a vertical outlet channel 1306 through aflow passage 1304. The flow passage 1304 may include a first horizontalportion 1308 connected to a second horizontal portion 1310 through avertical drop 1312. The vertical drop 1312 may be configured to balanceliquid hydrostatic pressure, similar to the vertical inlet and outletchannels, as explained above.

FIG. 14 illustrates a simplified view of a liquid circuit 1400,according to an embodiment. The liquid circuit 1400 includes a verticalinlet channel 1402 connected to a vertical outlet channel 1404 through aflow passage 1406. The flow passage 1406 may include a first horizontalportion 1408 connected to a second horizontal portion 1410 through avertical drop 1411. The liquid flow passage 1406 may also include athird horizontal portion 1412 connected to the second horizontal portion1410 through a vertical drop 1413. The vertical drops 1411 and 1413 maybe configured to balance liquid hydrostatic pressure, similar to thevertical inlet and outlet channels, as explained above. The flow passage1406 may include more vertical drops than those shown.

FIG. 15 illustrates a simplified view of a liquid circuit 1500.according to an embodiment. In this embodiment, a vertical inlet channel1502 is connected to a vertical outlet channel 1504 through a flowpassage 1506, which may be non-linear. When non-linear, the flow passage1506 may include offsetting portions such that a trough 1508 is offsetby a peak 1510. That is, the depth of the trough 1508 may be the sameabsolute distance as the height of the peak 1510.

Referring to FIGS. 13-15 , for example, the liquid circuits may or maynot include horizontal passages. For example, the liquid circuits mayinclude vertical flow channels connected to one another through variouspassages. Pressure balancing may occur directly in the vertical flowchannels. Additionally, the liquid circuits may be angled with respectto horizontal and vertical orientations.

FIG. 16 illustrates an isometric view of horizontal liquid panelassemblies connected to combined inlet channels and combined outletchannels 1600 according to an embodiment of the present disclosure. Oneor more panel assemblies 1602 may be stacked horizontally to form apanel stack 1640. The panel assemblies 1602 may be separated by membranesupport assemblies, such as described with respect to FIG. 4 . The panelassemblies 1602 may be fluidly connected proximate the left corner 1606to an inlet channel 1608. The inlet channel 1608 may be fluidlyconnected to an inlet header 1610. The panel assemblies are fluidlyconnected proximate the right corner 1616 to an outlet channel 1618. Theoutlet channel 1618 is fluidly connected to an outlet header 1620.Liquid, such as a desiccant, flows from the inlet header 1610 into theinlet channel 1608 and into the panel assembly 1602 at the corner 1606.The liquid passes through the panel assembly 1602 by traveling along aliquid path, such as described with respect to FIG. 4 . The liquid exitsthe panel assembly 1602 at the corner 1616 and flows into the outletchannel 1618 and into the outlet header 1620. The inlet channel 1608 mayprovide a pressure balancing function for low pressure supply to everypanel assembly 1602 in the panel stack 1640. The outlet channel 1618 mayprovide a pressure balancing effect for low back pressure to every panelassembly 1602 in the panel stack 1640.

FIG. 17 illustrates an isometric view of horizontal liquid panelassemblies connected to individual inlet channels and individual outletchannels 1700 according to an embodiment of the present disclosure. Oneor more panel assemblies 1702 may be stacked horizontally to form apanel stack 1740. The panel assemblies 1702 may be separated by membranesupport assemblies, such as described with respect to FIG. 4 . The panelassemblies 1702 may be fluidly connected proximate the right corner 1706to an inlet channel 1708. The inlet channel 1708 may be fluidlyconnected to an inlet header 1710. The panel assemblies may be fluidlyconnected proximate the left corner 1716 to an outlet channel 1718. Theoutlet channel 1718 may be fluidly connected to an outlet header 1720.Liquid, such as a. desiccant, flows flow from the inlet header 1710 intothe inlet channel 1708 and into the panel assembly 1702 at the corner1706. The liquid passes through the panel assembly 1702 by travelingalong a liquid path, such as described with respect to FIG. 4 . Theliquid exits the panel assembly 1702 at the corner 1716 and flows intothe outlet channel 1718 and into the outlet header 1720. The inletchannel 1708 may provide a pressure balancing function for low pressuresupply to every panel assembly 1702 in the panel stack 1740. The outletchannel 1718 may provide a pressure balancing effect for low backpressure to every panel assembly 1702 in the panel stack 1740.

FIG. 18 illustrates an isometric view of stacked horizontal liquid panelassemblies connected to inlet headers 1800 according to an embodiment ofthe present disclosure. One or more panel assemblies 1802 may be stackedhorizontally to form a panel stack 1850. One or more panel stacks 1850may be stacked to form a stack of panel stacks 1840. The panelassemblies 1802. may be separated by membrane support assemblies, suchas described with respect to FIG. 4 . All panel assemblies 1802 in onepanel stack 1850 may be fluidly connected proximate the right corner1806 to one inlet header 1808. The inlet header 1808 may be fluidlyconnected to an inlet channel 1810. The panel assemblies may be fluidlyconnected proximate the left corner 1816 to an outlet header 1818. Theoutlet header 1818 may be fluidly connected to an outlet channel 1820.Liquid, such as a desiccant, flows to flow along a fluid path 1860 fromthe inlet channel 1810 into the inlet header 1808 and into each panelassembly 1802 in the panel stack 1850 at the corner 1806. The liquidpasses through the panel assemblies 1802 by traveling along a liquidpath, such as described with respect to FIG. 4 . The liquid exits thepanel assemblies 1802 at the corner 1816 and flows into the outletheader 1818 and into the outlet channel 1820. The inlet channel 1810 mayprovide a pressure balancing function for low pressure supply to everypanel stack 1850 in the stack of panel stacks 1840. The outlet channel1820 may provide a pressure balancing effect for low back pressure toevery panel stack 1850 in the stack of panel stacks 1840.

FIG. 19 illustrates an isometric view of stacked horizontal liquid panelassemblies with external pressure balancing 1900 according to anembodiment of the present disclosure. One or more panel assemblies 1902may be stacked horizontally to form a panel stack 1950. One or morepanel stacks 1950 may be stacked to form a stack of panel stacks 1940.The panel assemblies 1902 may be separated by membrane supportassemblies such as described with respect to FIG. 4 . All panelassemblies 1902 in one panel stack 1950 may be fluidly connectedproximate the right corner 1906 to one inlet header 1908. The inletheader 1908 may be fluidly connected to a pressure control device suchas an inline regulating valve, a pressure regulating pump or other suchdevice capable of supplying fluid to all inlet headers at the samepressure. The panel assemblies may be fluidly connected proximate theleft corner 1916 to an outlet header 1918. The outlet header 1918 may befluidly connected to a pressure control device such as an inlineregulating valve, a pressure regulating pump or other such devicecapable of retrieving fluid from all outlet headers at the samepressure. Fluid, such as a desiccant, flows along a fluid path 1960 fromthe pressure control device into the inlet header 1908 and into eachpanel assembly 1902 in the panel stack 1950 at the corner 1906. Theliquid passes through the panel assemblies 1902 by traveling along aliquid path, such as described with respect to FIG. 4 . The liquid exitsthe panel assemblies 1902 at the corner 1916 and flows into the outletheader 1918 and into the pressure control device. The inlet pressurecontrol device may provide low pressure supply to every panel stack 1950in the stack of panel stacks 1940. The outlet pressure control devicemay provide low back pressure to every panel stack 1950 in the stack ofpanel stacks 1940.

Embodiments of the present disclosure may be used with various types ofenergy exchangers, such as liquid-to-air or liquid-to-liquid membraneenergy exchangers.

Embodiments of the present disclosure provide liquid panel assembliesthat are configured to balance internal liquid hydrostatic pressure andfrictional forces. As such, the total pressure within the liquid panelassemblies may be reduced, negated or otherwise neutralized. Thus,membrane bulge is substantially reduced or eliminated, which reduces thepotential for leaks and membrane creep.

Embodiments of the present disclosure provide a liquid panel assemblydivided into a plurality of separate liquid circuits, each of equallength and friction, so that liquid divides itself evenly among theliquid circuits and the flow through the liquid circuits is uniform. Thefluid circuits promote uniform flow distribution across the liquid panelassembly, thereby providing efficient operation and performance.

Embodiments of the present disclosure provide a liquid panel assemblythat creates pathways for controlled, uniform, flow distribution (suchas counterflow distribution) of liquid, such as desiccant, over aninternal membrane area. Further, the liquid panel assembly provides lowoperating pressure by offsetting the static pressure gain and frictionpressure loss as the liquid moves through the liquid circuits. Thevertical flow of liquid may be confined to small high speed channels,thereby reducing or eliminating the potential for buoyancy-drivenmal-distribution of liquid. The flow passages may be open (no fillerwick or mesh), thereby allowing for good contact of the liquid andmembrane, and low friction loss.

Embodiments of the present disclosure are not restricted to energyexchangers. Instead, embodiments of the present disclosure may be usedwith respect to any liquid panel frame that exchanges heat and/or massthrough a membrane, and where liquid pressure and flow distribution arecontrolled. For example, the liquid panel assemblies described above maybe used with desalination systems, water purification systems,evaporative cooling systems, systems configured to transfer heat/massbetween a liquid and a gas through a membrane, systems configured totransfer heat/mass between two liquid streams through a membrane, andthe like.

While various spatial and directional terms, such as top, bottom, lower,mid, lateral, horizontal, vertical, front and the like may be used todescribe embodiments of the present disclosure, it is understood thatsuch terms are merely used with respect to the orientations shown in thedrawings. The orientations may be inverted, rotated, or otherwisechanged, such that an upper portion is a lower portion, and vice versa,horizontal becomes vertical, and the like.

It is to be understood that the above description is intended to beillustrative, and not restrictive. For example, the above-describedembodiments (and/or aspects thereof) may be used in combination witheach other. In addition, many modifications may be made to adapt aparticular situation or material to the teachings of the variousembodiments of the disclosure without departing from their scope. Whilethe dimensions and types of materials described herein are intended todefine the parameters of the various embodiments of the disclosure, theembodiments are by no means limiting and are exemplary embodiments. Manyother embodiments will be apparent to those of skill in the art uponreviewing the above description. The scope of the various embodiments ofthe disclosure should, therefore, be determined with reference to theappended claims, along with the full scope of equivalents to which suchclaims are entitled. In the appended claims, the terms “including” and“in which” are used as the plain-English equivalents of the respectiveterms “comprising” and “wherein.” Moreover, in the following claims, theterms “first,” “second,” and “third,” etc. are used merely as labels,and are not intended to impose numerical requirements on their objects.Further, the limitations of the following claims are not written inmeans-plus-function format and are not intended to be interpreted basedon 35 U.S.C. § 112, sixth paragraph, unless and until such claimlimitations expressly use the phrase “means for” followed by a statementof function void of further structure.

This written description uses examples to disclose the variousembodiments of the disclosure, including the best mode, and also toenable any person skilled in the art to practice the various embodimentsof the disclosure, including making and using any devices or systems andperforming any incorporated methods. The patentable scope of the variousembodiments of the disclosure is defined by the claims, and may includeother examples that occur to those skilled in the art. Such otherexamples are intended to be within the scope of the claims if theexamples have structural elements that do not differ from the literallanguage of the claims, or if the examples include equivalent structuralelements with insubstantial differences from the literal languages ofthe claims.

What is claimed is:
 1. A liquid panel assembly for a liquid-to-airmembrane energy exchanger, the liquid panel assembly comprising: asupport frame having a plurality of liquid circuits through which aliquid is configured to flow, each of the liquid circuits comprising aninlet channel connected to an outlet channel through a plurality of flowpassages; and first and second semi-permeable membranes secured to firstand second sides of the support frame and enclosing the plurality ofliquid circuits, wherein the plurality of liquid circuits arefluidically isolated from one another.
 2. The liquid panel assembly ofclaim 1, wherein each of the plurality of liquid circuits is configuredto at least partially offset hydrostatic pressure gain with frictionpressure loss of the liquid that flows within the liquid circuit.
 3. Theliquid panel assembly of claim 1, wherein the one or more flow passagescomprises one or more counterflow passages.
 4. The liquid panel assemblyof claim 1, wherein a shape, porosity, or hydraulic diameter of one orboth of the inlet and the outlet channels is determined by a weight,viscosity, or flow speed of the liquid that is configured to flowthrough the plurality of liquid circuits.
 5. The liquid panel assemblyof claim 1, wherein a liquid inlet of the inlet channel is disposed atan upper corner of the support frame, and a liquid outlet of the outletchannel is disposed at a lower corner of the support frame, and whereinthe upper corner is diagonally located with respect to the lower corner.6. The liquid panel assembly of claim 1, wherein each of the inlet andthe outlet channels provide a flow alignment vane configured to directthe liquid to flow along a particular path.
 7. The liquid panel assemblyof claim 1, wherein the inlet and the outlet channels are configured toprovide support to the first and the second semi-permeable membranes,and wherein the inlet and the outlet channels are configured to providea sealing surface for at least a portion of the first and the secondsemi-permeable membranes.
 8. The liquid panel assembly of claim 1,wherein the inlet and the outlet channels are vertical and the pluralityof flow passages are horizontal.
 9. The liquid panel assembly of claim1, wherein a horizontal length of the plurality of flow passages exceedshalf a horizontal length of the support frame.
 10. The liquid panelassembly of claim 1, wherein the plurality of liquid circuits comprises:a first plurality of flow passages connected to a first inlet channeland a first outlet channel; and a second plurality of flow passagesconnected to a second inlet channel and a second outlet channel, andwherein the first plurality of flow passages is staggered with respectto the second plurality of flow passages.
 11. A liquid-to-air membraneenergy exchanger comprising a plurality of the liquid panel assembliesof claim 1, wherein the exchanger is configured to exchange energybetween air transmitted through the air channels and a liquidtransmitted through the liquid panel assemblies.
 12. The liquid-to-airmembrane energy exchanger of claim 11, wherein each of the supportframes of each of the plurality of liquid panel assemblies comprise aninlet member and an outlet member, both of which are connected to theplurality of liquid circuits.
 13. The liquid-to-air membrane energyexchanger of claim 12, wherein each inlet member and each outlet memberare integral to each respective support frame.
 14. The liquid-to-airmembrane energy exchanger of claim 13, wherein the inlet members of thesupport frames are configured to modularly engage one another, andwherein the outlet members of the support frames are configured tomodularly engage one another.
 15. The liquid-to-air membrane energyexchanger of claim 14, wherein the inlet members modularly engaged toone another to form an inlet manifold through which the liquid isconfigured to enter the plurality of liquid circuits of each of thesupport frames, and wherein the outlet members modularly engaged to oneanother to form an outlet manifold through which the liquid isconfigured to exit the plurality of liquid circuits of each of thesupport frames.